Sunday, September 14, 2008

Roguelikes for the blind?

Part of planning ahead is foreseeing potential problems and preparing for them beforehand. This means, I think about things like special needs. Because I may well have a need of it myself some day.

This is why I want a single-story house. If I wind up in a wheelchair some day, I don't want to deal with stairs. Plus, if I'm just old and enfeebled, I could fall down the stairs and break my back. Stairs are dangerous. Stairs kill.

Anyway, I was working on PyGame support in STEW, and looking at how PyGame handles keycode input. It occurred to me that it only has the capacity to tell me that keys have changed state, and it certainly doesn't appear to have any built-in accessibility features. Things like sticky-shift states would need to be accomidated at the application-layer. (Why sticky shift states? Well, a number of neurological disabilities could cause me to be unable to simultainously press the correct modifier keys with the correct target key.)

While I was thinking about this, it occurred to me that it would be nice to play a roguelike if I was blind. Of course, that would cause things to get much weirder, though. Ideally, I'd want to present an interface that could not only be read by screen readers, but could actually interface directly with a screen reader. This makes the whole visual representation of the map/rooms hard to present.

It also starts turning the result in to something more resembling a single-user MUD. I was actually thinking of keeping the internal representation of the map, but each room also needs an identifier -- a number will probably do, though we could just as easily do named rooms when something special comes along.

Then, there's the contents of the room. In general, I think I favor a bucket approach. A room has a certain size, and that size is filled by things in the room, with no relationship to the real-world shape of those things.

Melee combat is one thing that doesn't take in to account, though. If we're dealing with two creatures, we can easily take the empty space in the room and pick a random amount of space between the two opponents. However, some rooms are literally packed with creatures. While we can easily state that at most 6 or 9 creatures can attack you at once (depending on whether we want an implied hex map or a standard roguelike grid) you still have things like wands and breath weapons that can strike a large number, bounce off walls, and hit even more.

We could go with a literal roguelike grid, with the ability to look various attackable directions. We'd need short-cuts so that you could also just look at and attack a particular monster type. Sometimes attacking a monster would have implied movement to reach it.

It does seem to me that after thinking about it a little, we need to retain the roguelike map. We'll just need to have sufficient short-cuts to make visual representations of the map unneeded.

Here's a potential example of what it could look like:

You travel 10 feet. You turn east to follow the corridor. You travel 60 feet. You stop 10 feet from the doorway to room 1 on floor 7.

To the easy, you see:

a broken door

an orc chieftain

3 orc soldiers

To the west, you see:

an acid blob

This would break down the line-of-sight by cardinal direction. There could then be eleven direction labels, one for the eight cardinal directions, above, below, and around (for when you get swallowed by something).

Above isn't normally used on roguelikes. Below has common meaning when you're levitating over hazardous ground. Each of those should describe your cell only. The cardinal directions, however, cover more than just the usual lines. Each cardinal direction covers a 45 degree arc in that general direction.

The order is sorted first by monster type, and then by proximity to player. Once the list is sorted, it is compressed so that adjacent monsters in the list form a single line. This means that if 4 orcs are all 100 feet from you in the same general direction, they would show as "4 orcs", and if there is a line of 4 orcs coming toward you at 70, 80, 90, and 100 feet from you they would also show as "4 orcs". If there was a bat amist the orcs, though, in the earlier cast it would always continue to bundle the orcs, but in the later case it would likely wind up splitting the orcs in to two groups with a bat in the middle.

You would need to be able to query how close a given monster type is, what monsters are at a given distance, as well as what monsters are in a given attackable direction.

Doors will also need identifiers. I think we can go with letters, so that a room number + door letter unique identifies a door. This would allow us to say:

You enter room 6. It is 30x60. There are four doors here (A, B, C, D).

There appear to be no monsters in the room. The room contains:

...amulets...

...gems...

...wands...

That is, we identify doors solely by the letter. While we could state, "Door A is on the north wall, and 20 feet from the north-east corner." It just starts getting harder to remember, and having less value. Likewise, we can drop the number of steps taken when walking the corridors. When intersections are presented we should state the direction we came from, and the directions now available. When monsters are nearby the behavior should be as earlier described whether in a room or not.

When monsters are not visible in a room, we can do as described in the most recent example, and bundle all objects together. While this doesn't make as much sense on an open-plain map, rooms are small enough that it makes little difference where an object is within the room. They should still be sorted by proximity, so after you take the first object you can always modify your path. (Assuming we don't short-cut that behavior when in a room and monsters aren't around. I wouldn't be against picking up objects as being 1 turn activities -- particularly if we make entering a room a multi-turn activity.)

Yeah, we can see where I suffer from a case of feature-bloat. Particularly for this project.